Collagen corneas restore damaged sight

People with damaged corneas have had their sight restored by implants made of collagen – which eventually anchor themselves into the recipient’s eye.

Corneal damage, which results in seriously blurred sight, is currently treated either by implanting corneas from a human donor – which are in short supply – or an unsightly prosthesis, which looks like a pinhole camera.

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Now May Griffith at Linköping University in Sweden and colleagues have developed a cornea from collagen moulded to the shape and size of a natural human cornea. “It looks like a contact lens,” says Griffith. The difference is that this “biosynthetic” cornea encourages the person’s own cells to grow into its matrix, since it is made out of a similar substance to a natural one.

Griffith’s team inserted their biosynthetic corneas into the eyes of 10 people with corneal damage. Nylon sutures across the cornea held it in place, and the recipients were put on immunosuppressant drugs for six weeks to prevent rejection.

Nerves regrow

After two years, the cornea in all the recipients had become filled with the patients’ own cells, anchoring it to the eye. Nerves also grew across all of the corneas, which is important for cell survival and to maintain the blink response.

Six of the people now have their vision restored. The other four still have a visual “haze” which Griffith thinks is due to scarring from the sutures, which were placed across the middle of the cornea.

“I think Griffith’s work has the potential to revolutionise the field of cornea transplantation,” says Christopher Ta, professor of ophthalmology at Stanford University in California. “It is possible [we will] see widespread use of this type of engineered cornea in the next five years.”